The Dolphins signed Allen to a four-year deal and ironically completed a swap with the Giants when the Dolphins released longtime starter Sam Madison, who later signed with the Giants.
Miami has maintained that the defensive secondary will be a priority this offseason and that remains the case. The team has either released or declined to sign three of the four starters from last year's secondary, in addition to nickel back Reggie Howard. Miami has signed two players now, Allen and Renaldo Hill, to help the position.
In another free agent signing, the team also announced it had inked a deal with former San Diego tight end Justin Peelle.
Peelle, 27, was a fourth-round pick of the Chargers in 2002 and has four career touchdown catches while being a backup to Antonio Gates.